Speaking exclusively to The Bendigo Advertiser, Mr Gibbons said he was angry at a Coalition “smear campaign” against his party and the Prime Minister.

He said his choice of words was inappropriate, but the ideas behind the comments were valid.

“If I see something I think is inappropriate and I think the opposition deserves to be attacked, I’ll continue to attack them," he said.

“I’ve apologised for the choice of words during this morning’s tweets.

“It will not stop me from using Twitter to attack the opposition if they deserve it.”

Mr Gibbons said he would not apologise to the Liberal members in person, as the comments were made on Twitter.

“The offending words were on Twitter, so I’ve apologised on Twitter,” he said.

“You can’t change who you are.

“If people don’t like it, that’s fine, I don’t have a problem with that.”

He said the opposition should be asking the government about the Murray Darling Basin plan, Gonski Report and other policy initiatives.

“They have been running a smear campaign against the government and PM for the last week or 10 days knowing they have no evidence to suggest anything inappropriate done by the PM either now or 20 years ago,” he said.

Mr Gibbons removed the comments from Twitter.

Comment is being sought from Mr Abbott and Ms Bishop.

EARLIER THE AGE REPORTED

LABOR MP Steve Gibbons has caused a stir by calling Tony Abbott a ''gutless douchebag'' and Julie Bishop a ''narcissistic bimbo'' on Twitter.

It is Mr Gibbons' use of the word ''bimbo'' that will cause the biggest headaches for Labor given Prime Minister Julia Gillard's aggressive campaign against the Opposition Leader's alleged misogyny.

Steve Gibbons later offered a qualified apology on Twitter.

Mr Gibbons later offered a qualified apology on Twitter, saying, ''Apologies to those offended by the use of the word Bimbo [sic]. I'll replace that word with 'Fool' [sic].'' He also deleted the offending tweets.

Mr Gibbons has a history of provocative statements. He called Kevin Rudd a ''psychopath with a giant ego'', during the former prime minister's leadership challenge earlier this year.

Senior cabinet ministers are increasing their pressure on Ms Bishop, calling on the Deputy Opposition Leader to respond to reports that she spoke on the phone last week to former union bagman and ''self-confessed fraudster'' Ralph Blewitt as well as meeting him for coffee on Friday.

''Yesterday in the press conference she said she had only spoken to Mr Blewitt once,'' said the Labor cabinet minister, Anthony Albanese, on ABC news.

''We find out today in the Fairfax press there are reports that she also had a phone conversation with Mr Blewitt last week... So Julie Bishop has more questions to answer,'' Mr Albanese said.

This attack follows Mr Albanese's statement on Tuesday that Ms Bishop's position has become "untenable" after accusing the Prime Minister of criminal conduct when she was a lawyer representing her former boyfriend, the disgraced union official Bruce Wilson, in the 1990s. Mr Blewitt admits to being Mr Wilson's partner in the alleged fraud.

Ms Bishop described her Friday meeting with Mr Blewitt as impromptu and coincidental - ''a 10 minute conversation at most''.

''I was in Melbourne for other purposes,'' Ms Bishop said on Tuesday. ''I got a call from Mike Smith (former 2UE broadcaster)... who said they were in a coffee shop and would I like to meet with Mr Blewitt.

''It was on the route that I was taking and I stopped by''.

Fairfax Media is waiting on a response from Ms Bishop's office.

Trade Minister Craig Emerson said if the reports of a second conversation between Ms Bishop and Mr Blewitt are true, the Deputy Opposition Leader ''must resign or be sacked''.